1. Field of Invention
This embodiment relates to a countermeasure process whereby military and civil commercial aircraft under attack by an anti aircraft infrared heat seeking missile is able to effectively deflect attacking missile by dispensing appropriate and distinctive fluid spray behind its tailpipe in the wake of exhaust plume, and into the path of trailing hostile missile.
Military and civil aircraft could come under an attack by a hostile infrared heat seeking missile. Such infrared heat seeking missile homes in on the target aircraft heat source such as the jet engine exhaust, and is fused to detonate when it approaches said target very close or enters its tailpipe. To accomplish said tracking and eventual detonation in close proximity to target, typical heat seeking missile uses combination of passive guidance control system to keep the infrared emission from the target in sight and an active optical target detector to determine when it is within the correct detonation range. This requires that the missile maintain an unobstructed line of sight with target aircraft heat source, referred to as being locked on, prior to launch and during its entire flight to this target.
The active optical target detector consists of numerous laser emitter and sensor diodes arranged around the outside of the missile airframe immediately behind the flight fins. When the missile is in flight, the active optical detector is constantly emitting number of laser beams at a set frequency forward in a radial pattern and in the direction of the target aircraft. When the missile approaches sufficiently close to its intended target, the laser beams will reflect off some part of the aircraft body and be detected by its sensor diodes. The optical target detector then recognizes that missile is at correct burst range and triggers its annular blast fragmentation warhead to detonate and destroy the intended target.
The passive heat seeking elements for the guidance control are located and housed in the nose of missile and behind the infrared filter plastic dome.
By applying appropriate and distinctive substance in a fluid spray to coat this plastic dome as described in present and preferred embodiment, the received infrared energy sources from the targeted aircraft would be sufficiently distorted and degraded to blind and hinder effective missile guidance control.
Of the two systems on the missile which are important to neutralize, the passive guidance control in the seeker, located behind the plastic dome, presents a much larger target area than the laser emitter and sensor diodes of the optical target detector, and is therefore a primary candidate and easier of the two on which to focus the countermeasure process in this embodiment, using the said fluid spray.
2. Description of Prior Art
There are currently several proposed and applied countermeasures generally known and available to the targeted aircraft:                1. Ejecting secondary bright infrared sources and dispensable, such as flare salvo and infrared beacons, to draw heat seeking missile away from targeted aircraft and towards these secondary decoys.        2. Steering aircraft into sun to draw heat seeking missile in that direction and then executing rapid evasive maneuver away from missile trajectory.        3. Shining infrared laser beams rearward of aircraft and into path of trailing missile, intended to confuse missile guidance control system or to cause its active optical target detector to initiate a premature detonation but at a safer distance.        4. Significantly cooling exhaust gases to as near the ambient air temperature surrounding the aircraft as possible, to reduce the targeted aircraft infrared emission. Such technique is referred to as cloaking or infrared stealth masking device.        These prior art countermeasure process currently available to targeted aircraft suffer from several significant drawbacks:        1. Not all countermeasures are universally, economically and readily available or applicable to both military and civil aircraft targets.        2. Available countermeasures are dependent on time of day, altitude and weather conditions. For example, using sun for a decoy would be ineffective countermeasure at night or when thick clouds hide the sun. At such times, the targeted aircraft infrared heat emission is the predominant source to the attacking missile guidance control system.        3. Available countermeasures are dependent on agility and structural integrity of targeted aircraft, along with ability of aircraft pilot to detect, react and execute rapid and intricate evasive maneuvers against large acceleration forces. A civil or military transport aircraft would be unable to execute rapid and agile evasive maneuver in a manner that a military jet fighter could. In addition, even a military jet fighter may not be able to evade the attacking heat seeking missile under all conditions, considering that the missile offers little opportunity for warning before impact.        4. Applicable countermeasures are dependent on targeted aircraft rearward pulsing laser beams effectively hitting, jamming missile guidance control system, and its optical target detection in time to prevent hitting the targeted aircraft.        5. Countermeasure, whereby the targeted aircraft is emitting laser beams rearward to trick attacking missile optical target detector to initiate a premature detonation may not be effective if the countermeasure system of the missile is immune to such targeted aircraft defensive measures.        6. Effectiveness of aircraft countermeasures are dependent upon knowing existing missile infrared parameters and detailed characteristics of its guidance and optical target detection systems, along with anticipating timely new advances in missile's own countermeasure capability and the ability to quickly and economically compensate its own defenses in response.        7. Expensive, complicated and lengthy retrofit and modifications of existing aircraft for cooling exhaust gases may not be well suitable for most civil and military aircraft.                    For example, in U.S. Pat. No. 6,098,042 to Sawaruk (1990) indicates that his present preferred embodiment is a complex system made up of multiple subsystems which may be used in whole or in part to accomplish various missions with regard to infrared suppression on a variety of vehicles. An example of which would be external cryogenic ejector nozzles applied to rotary aircraft exhaust pipes.                        